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From: John Hubbard <jhubbard@nvidia.com>
To: Jens Axboe <axboe@kernel.dk>,
	jhubbard.send.patches@gmail.com, Jan Kara <jack@suse.cz>,
	Christoph Hellwig <hch@infradead.org>,
	Dave Chinner <dchinner@redhat.com>,
	"Darrick J . Wong" <djwong@kernel.org>,
	Theodore Ts'o <tytso@mit.edu>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Miklos Szeredi <miklos@szeredi.hu>,
	Andrew Morton <akpm@linux-foundation.org>,
	Chaitanya Kulkarni <kch@nvidia.com>
Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-xfs@vger.kernel.org, linux-mm@kvack.org,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/6] iov_iter: new iov_iter_pin_pages*(), for FOLL_PIN pages
Date: Sun, 27 Feb 2022 14:09:39 -0800	[thread overview]
Message-ID: <db3b5263-864e-dbb8-b3d9-075b6283e5bf@nvidia.com> (raw)
In-Reply-To: <06469550-a679-145f-b16e-2f1ffc0b07af@kernel.dk>

On 2/27/22 13:57, Jens Axboe wrote:
...
>> +			return res;
>> +		return (res == n ? len : res * PAGE_SIZE) - *start;
> 
> Trying to be clever like that just makes the code a lot less readable. I
> should not have to reason about a return value. Same in the other
> function.
> 

No argument there. This was shamelessly lifted from
iov_iter_get_pages(), and I initially calculated that keeping it
identical to that known-good code, where possible, was better than
fixing it up.

However, I'll go ahead and simplify it--with pleasure--based on this
feedback.


thanks,
-- 
John Hubbard
NVIDIA

  reply	other threads:[~2022-02-27 22:09 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-27  9:34 [PATCH 0/6] block, fs: convert most Direct IO cases to FOLL_PIN jhubbard.send.patches
2022-02-27  9:34 ` [PATCH 1/6] mm/gup: introduce pin_user_page() jhubbard.send.patches
2022-02-27  9:34 ` [PATCH 2/6] iov_iter: new iov_iter_pin_pages*(), for FOLL_PIN pages jhubbard.send.patches
2022-02-27 21:57   ` Jens Axboe
2022-02-27 22:09     ` John Hubbard [this message]
2022-02-28 22:49     ` John Hubbard
2022-02-27  9:34 ` [PATCH 3/6] block, fs: assert that key paths use iovecs, and nothing else jhubbard.send.patches
2022-02-27 21:58   ` Jens Axboe
2022-02-27 22:12     ` John Hubbard
2022-02-27 22:15   ` Al Viro
2022-02-27 22:27     ` John Hubbard
2022-02-28  3:29     ` John Hubbard
2022-02-27  9:34 ` [PATCH 4/6] block, bio, fs: convert most filesystems to pin_user_pages_fast() jhubbard.send.patches
2022-02-27 21:59   ` Jens Axboe
2022-02-27 22:13     ` John Hubbard
2022-02-27  9:34 ` [PATCH 5/6] NFS: direct-io: convert to FOLL_PIN pages jhubbard.send.patches
2022-02-27  9:34 ` [PATCH 6/6] fuse: convert direct IO paths to use FOLL_PIN jhubbard.send.patches
2022-02-28 15:59   ` Miklos Szeredi
2022-02-28 21:16     ` John Hubbard
2022-03-01  9:41       ` Miklos Szeredi
2022-03-02  8:07         ` John Hubbard

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